The present invention relates to a motor vehicle with an engine, a transmission with a device for changing the transmission ratio, a control device, and a ratio-selector device. The transmission has a first operating mode in which a change of the transmission ratio is initiated by the control device, and a second operating mode in which a change of the transmission ratio is initiated by the ratio-selector device.
Motor vehicles of this type are commonly known. The selection between the first and second operating mode is made by means of a switching element that is operated by the driver of the vehicle.
This has the inherent drawback that in order to switch from one operating mode to the other requires a deliberate act of the driver. This is inconvenient for the driver, and it often leads to situations where the operating mode is either left unchanged or is switched too late, e.g., because the driver may be inattentive or indisposed. As a result, the transmission remains in an operating mode that is inappropriate for the situation, which has serious negative consequences for the driving safety of the vehicle.
The invention therefore has the objective of providing a motor vehicle in which the switch-over from one operating mode to the other does not require a deliberate act of the driver, so that when a switch of operating modes is needed, the driver will not necessarily be required to take action, and thus will not be caused by the aforementioned reasons to neglect the switch of operating modes.
This objective is desirable, because it not only increases the operating convenience for the driver, but it also significantly enhances the driving safety of the vehicle.
According to the invention, the foregoing objective is met by a motor vehicle of the type described above, wherein a switch-over between the first operating mode and the second operating mode can be performed automatically under the control of the control device.
Preferably, the control device directs the switch-over from one operating mode to the other in response to at least one signal.
In a preferred embodiment, a first signal causes a switch-over to the first operating mode where a shift of the transmission ratio is initiated by the control device, and a second signal causes a switch-over to the second operating mode where a shift of the transmission ratio is initiated by the ratio-selector device.
An advantageous embodiment of the invention provides the option of omitting the switch-over to the second operation mode. For example, in a case where the switch-over between operating modes is coupled to the operation of a car telephone by the driver, as will be discussed below in further detail, the transmission would remain in the first operating mode after a telephone call has been completed.
Preferably, the switch-over to the second operating mode through the second signal is left out, if the first operating mode was selected already before the first signal occurred.
There is an advantage, if the switch-over to the second operating mode, where ratio-changes are initiated by the ratio-selector device, is made without a simultaneous shift of the transmission ratio, so that the transmission ratio that was previously selected by the control device during operation in the first operating mode remains in effect.
A preferred embodiment of the invention is distinguished in that the first signal and the second signal are generated by an electronic accessory device, particularly a communication device such as a mobile telephone.
In an example of a preferred embodiment of the invention, the first signal (which initiates the switch-over to the first operating mode where transmission-ratio shifts are initiated by the control device) is at least representative of an incoming or outgoing telephone call that is either taking place or is intended by the driver.
Also with preference, the second signal (which initiates the switch-over to the second operating mode where transmission-ratio shifts are initiated by the ratio-selector device) is at least representative of a telephone call having been completed or of the driver""s intent to end a telephone call.
The novel features that are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.